Browse Prior Art Database

Forming Green Sheet Ceramic

IP.com Disclosure Number: IPCOM000086280D
Original Publication Date: 1976-Aug-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

McIntosh, CM: AUTHOR [+2]

Abstract

In this process, ceramic green sheet is formed by calendering dry powder.

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Forming Green Sheet Ceramic

In this process, ceramic green sheet is formed by calendering dry powder.

The conventional method for forming ceramic green sheet is by the slip- casting doctor blade process wherein a liquid suspension made up of a suitable mixture of solvent, ceramic powder, and a resin plasticizer are combined, formed into a sheet by doctor blading, and drying the sheet. Subsequently, the flexible ceramic green sheets are processed by punching via holes, printing patterns and filling the via holes with a suitable conductive paste, laminating the various sheets, and sintering.

This process utilizes two separate phases namely (1) the forming of a dry powder of resin coated ceramic particles, and (2) hot forming the powder into a flexible sheet. This process results in better green sheet dimensional stability, more predictable properties, and closer processing tolerances.

In the first phase, the slip is prepared in the usual way by combining ceramic powder, normally Al(2)O(3), a suitable solvent, and a resin with plasticizer, and blending in an open abrasion resistant high-speed blender. During the blending operation, DI water is slowly added which causes the resin to precipitate and to settle out rapidly. The supernatant liquid is removed by vacuum filtering or spray drying which leaves a moist residue formed of a loose, soft plastic mass which indicates the presence of the resin. The residue is dried completely at an elevated temperature and subseque...